Antenna systems having a plurality of antennas are known to provide various structural advantages. Particularly, the assembly of an antenna system in a single structural module allows mechanical and electrical components to be shared between the antennas. The antennas in a known antenna system may, for example, share a housing, a base, PCB circuitry, and exterior electrical connections for transmitting and receiving electrical signals. However, when the antennas within the antenna system are arranged close to each other, the antennas suffer from mutual interference of their respective radiating patterns.
U.S. Pat. No. 6,917,340 relates to an antenna system having two antennas. In order to reduce the coupling and interference effects, one of the two antennas is subdivided into segments which have an electrical length corresponding to three-eighths of the wavelength of the other antenna. Further, the segments of the first antenna are electrically interconnected via electric reactance circuits which possess sufficiently high impedance in the frequency range of the second antenna and sufficiently low impedance in the frequency range of the first antenna.
Even though the teaching of the U.S. Pat. No. 6,917,340 reduces interference in the radiation patterns of the two antennas, the design and assembly of the antenna system is complicated due to the inclusion of the electric reactance circuits. Further, the soldered connection of the electric reactance circuits to the antennas introduces unacceptable frequency variances.